1. Field of the Invention
The present invention relates to a ceramic circuit board and a method of making the same.
2. Description of the Related Art
A ceramic circuit board employing ceramic substrate with excellent heat dissipation ability and high reliability are widely used in electrical or electronic products, such as high power electrical modules, and high power light emitting diodes.
Several types of techniques have been used for making ceramic circuit boards. For instance, low-temperature co-fired ceramic (LTCC), high-temperature co-fired ceramics (HTCC), direct bonded copper (DBC), and direct plated copper (DPC) processes have been used. The DPC process on metalized ceramic substrate was originally created to replace the DBC process because of its better electrical, thermal and mechanical performance. The entire DPC process basically comprises the steps of defining holes in the ceramic substrate, sputtering a copper film onto the ceramic substrate, forming a dry film onto the copper film, forming a circuit pattern with exposure and development, plating copper leads, removing the dry film and etching the seed metal copper, and so on. Further detailed information can be found in U.S. Patent Pub. No. 2011/0079418.